Medieval masonry towers are a prominent and ubiquitous feature of the Mediterranean Basin and the Balkan Peninsula. Many are in ruins and most have yet to be studied. We surmise that they were built for protection, so that they are typically associated with the architecture of an "age of insecurity." Professor Slobodan Ćurčić, who dedicated his career to the study of medieval architecture, has nourished a special interest in these buildings. Honoring Professor Ćurčić, I offer this chapter surveying a discrete group of seven Late Byzantine (fourteenth to sixteenth centuries) freestanding towers in northern Greece.